A kind of water-based pigment inkjet ink suitable for wall and preparation method thereof

Abstract

The present application relates to the field of inkjet inks, and in particular to a water-based pigment inkjet ink suitable for walls and a preparation method thereof. A water-based pigment inkjet ink suitable for walls comprises the following raw materials in parts by weight: 10-20 parts of water-based polyurethane; 0.5-3 parts of wetting agent; 0.1-1 parts of bactericide; 0.1-1 parts of pH regulator; 15-35 parts of water-based resin-free color paste; 10-30 parts of a first solvent; and 20-50 parts of deionized water. The present application has the characteristics of improving the spraying effect and color fastness of water-based pigment inkjet ink.

Description

Technical Field

[0001] The present application relates to the field of inkjet inks, and in particular to a water-based pigment inkjet ink suitable for walls and a preparation method thereof. Background Art

[0002] With the increasing maturity of various printing software and printing equipment, the use of digital printing to print wall prints has become a product of the combination of emerging technology and traditional advertising culture. Digital printing not only effectively reduces the production cost of wall prints, but also improves its personalization and graphic rendering effect.

[0003] In the field of digital printing, water is used instead of organic solvents to produce water-based pigment inkjet inks, which has the advantages of reducing VOC emissions and reducing pollution to the environment; being non-flammable and non-explosive, reducing safety hazards; being non-toxic and harmless, which is beneficial to the health of those who come into contact with it; saving petroleum resources, and being beneficial to the sustainable development of society. Therefore, water-based pigment inkjet inks have now become a development trend in the digital printing industry.

[0004] However, since the surface tension of water is higher than that of organic solvents commonly used in inks, the stability of water-based pigment inkjet inks is greatly affected, which can easily cause pigment particles to agglomerate or settle, reducing the ink spraying effect and resulting in poor adhesion of water-based pigment inkjet inks on the wall. Summary of the invention

[0005] In order to improve the spraying effect and color fastness of water-based pigment inkjet ink, the present application provides a water-based pigment inkjet ink suitable for walls and a preparation method thereof.

[0006] In the first aspect, the present application provides a water-based pigment inkjet ink suitable for walls, which adopts the following technical solution:

[0007] A water-based pigment inkjet ink suitable for walls, comprising the following raw materials in parts by weight:

[0008] 10-20 parts of waterborne polyurethane;

[0009] Wetting agent 0.5-3 parts;

[0010] 0.1-1 part of fungicide;

[0011] pH regulator 0.1-1 part;

[0012] 15-35 parts of water-based resin-free color paste;

[0013] 10-30 parts of the first solvent;

[0014] 20-50 parts of deionized water.

[0015] By adopting the above technical scheme, the film-forming property of the water-based polyurethane is good, which is conducive to the water-based pigment inkjet ink to form a durable film on the wall, making it difficult for water droplets to penetrate, thereby improving the waterproofness of the water-based pigment inkjet ink, and the water-based polyurethane contains more polar groups, which is convenient for cross-linking reaction to form a stable cross-linking structure to consolidate the internal structure of the water-based pigment inkjet ink, so that the stability of the internal structure of the inkjet ink is improved, thereby improving the color fastness and water resistance of the inkjet ink; secondly, under the action of the wetting agent, the surface tension of the water-based pigment inkjet ink can be reduced, so as to further improve the stability of the inkjet ink. The pH regulator can improve the overall fluidity of the inkjet ink, thereby improving the spraying effect of the inkjet ink, which is conducive to achieving better printing effect and adhesion effect; and, under the regulation of the pH regulator, the inkjet ink can be further maintained stable, which is conducive to further improving the spraying effect and color fastness of the inkjet ink; at the same time, the compatibility of the inkjet ink system is improved through the first solvent, thereby further improving the internal structure stability of the inkjet ink, and providing a moisturizing effect for the inkjet ink, so that the fluidity of the inkjet ink is improved, thereby achieving a further improvement in the spraying effect and color fastness of the water-based pigment inkjet ink.

[0016] Preferably, the waterborne polyurethane is chitosan-modified waterborne polyurethane, the raw materials for preparing the chitosan-modified waterborne polyurethane include quaternized chitosan and waterborne polyurethane, and the weight ratio of the quaternized chitosan to the waterborne polyurethane is (1.8-2.6):(45-65).

[0017] By adopting the above technical scheme, under the modification effect of quaternized chitosan, it is beneficial to improve the film-forming property of water-based polyurethane. At the same time, quaternized chitosan has good hydrophilicity and compatibility, which is beneficial to improve the compatibility of water-based polyurethane in the water-based pigment inkjet ink system, and through the dispersing effect of quaternized chitosan, the water-based polyurethane is evenly dispersed in the inkjet ink system, so as to further improve the stability of the inkjet ink, and the inkjet ink is evenly film-formed, thereby further improving the color fastness and water resistance of the water-based pigment inkjet ink; secondly, through the moisturizing effect of chitosan, the overall fluidity of the inkjet ink is effectively improved, which is beneficial to further improve the spraying effect of the water-based pigment inkjet ink, so that the water-based pigment inkjet ink achieves better printing effect and adhesion effect; and, under the antibacterial effect of chitosan, the reproduction of various algae and bacteria can be reduced to reduce the influence of bacteria on the stability of the inkjet ink, thereby further realizing the improvement of the spraying effect and color fastness of the water-based pigment inkjet ink.

[0018] Preferably, the quaternized chitosan is organic acid-modified quaternized chitosan, the raw materials for preparing the organic acid-modified quaternized chitosan include quaternized chitosan, organic acid and catalyst, and the weight ratio of the quaternized chitosan, organic acid and catalyst is (3-8): (7-18): (1.5-3).

[0019] By adopting the above technical scheme, under the catalytic action of the catalyst, the quaternary ammonium chitosan is modified by an organic acid, so that the surface activity of the quaternary ammonium chitosan is improved, and the quaternary ammonium chitosan can be better dispersed in the reaction solution, so as to effectively modify the water-based polyurethane, thereby effectively improving the film-forming property of the water-based polyurethane, and effectively exerting the dispersing effect of the quaternary ammonium chitosan, so that the water-based polyurethane can be more evenly dispersed in the inkjet ink system, so as to achieve the effect of further improving the stability of the inkjet ink, and further realizing the effective improvement of the color fastness and spraying effect of the water-based pigment inkjet ink.

[0020] Preferably, the catalyst is selected from sodium hypophosphite.

[0021] Preferably, the organic acid comprises citric acid and tartaric acid, and the weight ratio of the citric acid to the tartaric acid is (1.2-1.5):1.

[0022] By adopting the above technical scheme, citric acid and tartaric acid are combined in a specific ratio, so that the two can produce an alternating copolymer through polycondensation, improve the structural stability, effectively modify the quaternary ammonium chitosan, and then effectively improve the surface activity and dispersing effect of the quaternary ammonium chitosan, so as to give full play to the modification and dispersing effect of the quaternary ammonium chitosan on the water-based polyurethane, thereby further improving the internal structural stability and film-forming property of the inkjet ink, which is conducive to further improving the spraying effect and color fastness of the water-based pigment inkjet ink; and both citric acid and tartaric acid can be used as quaternary ammonium The invention relates to a cross-linking agent of chitosan and waterborne polyurethane, and then the quaternary ammonium chitosan and the waterborne polyurethane are cross-linked to further give full play to the modification effect of the quaternary ammonium chitosan on the waterborne polyurethane, so that the film-forming property of the waterborne polyurethane is further improved, and it is beneficial to improve the connection tightness of the internal structure of the waterborne pigment inkjet ink, so as to further improve the color fastness and water resistance of the waterborne pigment inkjet ink, and at the same time effectively exert the moisturizing effect of the quaternary ammonium chitosan, so that the overall fluidity of the inkjet ink is further improved, which is beneficial to further improve the spraying effect of the waterborne pigment inkjet ink.

[0023] Preferably, the quaternized chitosan is N-trimethyl chitosan.

[0024] By adopting the above technical scheme, N-trimethyl chitosan has good compatibility, which is beneficial to further improve the compatibility of water-based polyurethane in the water-based pigment inkjet ink system, and the use of N-trimethyl chitosan can promote the formation of chemical bonds between quaternary ammonium chitosan and water-based polyurethane, so as to give full play to the modification effect of quaternary ammonium chitosan on water-based polyurethane, so that the film-forming property of water-based polyurethane can be effectively further improved, and it is beneficial to further consolidate the internal structure of water-based pigment inkjet ink, thereby achieving further improvement in the color fastness of water-based pigment inkjet ink.

[0025] Preferably, the waterborne polyurethane is a polyester-polyether hybrid waterborne polyurethane, and the raw materials for preparing the polyester-polyether hybrid waterborne polyurethane include waterborne polycarbonate polyurethane, waterborne polyether polyurethane, deionized water and weakly alkaline amine compounds. The weight ratio of the waterborne polycarbonate polyurethane, waterborne polyether polyurethane, deionized water and weakly alkaline amine compounds is (1-2): (1-2): (12-18): (0.2-0.7).

[0026] By adopting the above technical scheme, in a weakly alkaline environment, water-based polycarbonate polyurethane and water-based polyether polyurethane are combined in a certain proportion, so that the two can complement each other, allowing the water-based polyurethane to be used as an adhesion promoter, thereby further improving the color fastness of the inkjet ink, and can also effectively improve the water resistance of the water-based polyurethane, thereby effectively achieving further improvement of the water resistance of the water-based pigment inkjet ink.

[0027] Preferably, the weakly alkaline amine compound is selected from one of ammonia water and triethanolamine.

[0028] Preferably, the wetting agent is selected from one or more polyether siloxane copolymers.

[0029] Preferably, the bactericide is selected from one or both of the bactericide MBT-25 and the preservative K26.

[0030] Preferably, the pH regulator is selected from one of ammonia water and urea.

[0031] Preferably, the first solvent is selected from one or more of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,5-pentanediol, polyvinyl alcohol, sorbitol, isopropanol, ethanol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, diethylene glycol monobutyl ether and triethylene glycol butyl ether.

[0032] In a second aspect, the present application provides a method for preparing a water-based pigment inkjet ink suitable for walls, using the following technical solution:

[0033] A water-based pigment inkjet ink suitable for walls, comprising the following steps:

[0034] First, the first solvent, deionized water, bactericide and pH adjuster are stirred and mixed for 20-30 minutes, and then a wetting agent is added and stirred for 20-30 minutes to obtain a clear liquid; then, water-based polyurethane is added and stirred for 30-40 minutes, and then a water-based resin-free color paste is added and stirred for 30-40 minutes to obtain an inkjet ink preform; finally, the inkjet ink preform is negatively pressure filtered at 0.02-0.06MPa through a double-layer hydrophilic filter membrane, and the filtrate is collected to obtain a water-based pigment inkjet ink suitable for walls.

[0035] By adopting the above technical scheme, the water-based pigment inkjet ink prepared by the above preparation method has the characteristics of stable structure, which is beneficial to improving the color fastness and water resistance of the water-based pigment inkjet ink, and effectively improving the stability of the inkjet ink, thereby achieving an improvement in the overall fluidity of the water-based pigment inkjet ink, and thus improving the spraying effect of the water-based pigment inkjet ink.

[0036] Preferably, the preparation method of the polyester-polyether hybrid waterborne polyurethane is: deionized water and a weakly alkaline amine compound are stirred and mixed to obtain a weakly alkaline solution; then, waterborne polycarbonate polyurethane and waterborne polyether polyurethane are added to the weakly alkaline solution, and stirred and mixed for 30-40 minutes to obtain a polyester-polyether hybrid waterborne polyurethane.

[0037] By adopting the above technical scheme, the above preparation method is conducive to fully mixing and modifying the waterborne polycarbonate polyurethane and the waterborne polyether polyurethane, thereby obtaining a polyester-polyether mixed waterborne polyurethane with a stable structure and strong surface properties.

[0038] Preferably, the preparation method of the organic acid modified quaternary ammonium chitosan is: add an organic acid and a catalyst into deionized water, heat to 55-65°C, and stir and mix for 30-40 minutes; then, add quaternary ammonium chitosan and stir to react for 1-2 hours; after the reaction is completed, precipitate with ethanol, wash and filter, then collect the filter and dry to obtain organic acid modified quaternary ammonium chitosan, wherein the weight ratio of the quaternary ammonium chitosan, organic acid, catalyst and deionized water is (3-8): (7-18): (1.5-3): (55-65).

[0039] By adopting the above technical scheme, the organic acid-modified quaternary ammonium chitosan prepared by the above preparation method can effectively improve the surface activity of the quaternary ammonium chitosan, which is beneficial to promote the composite modification of the organic acid-modified quaternary ammonium chitosan and water-based polyurethane, and is beneficial to improve the antibacterial effect of the quaternary ammonium chitosan, thereby achieving effective improvement in the stability of the water-based pigment inkjet ink, so as to improve the spraying effect and color fastness of the water-based pigment inkjet ink.

[0040] Preferably, the preparation method of the chitosan modified waterborne polyurethane is: uniformly mix the organic acid modified quaternary ammonium chitosan and the polyester-polyether mixed waterborne polyurethane, heat to 70-85° C., and stir for 2-3 hours to obtain the chitosan modified waterborne polyurethane.

[0041] By adopting the above technical scheme, under the modification and cross-linking action of organic acid, the organic acid-modified quaternary ammonium chitosan can be fully cross-linked and modified with the polyester-polyether mixed waterborne polyurethane, thereby obtaining a chitosan-modified waterborne polyurethane with stable structure and good film-forming property, thereby further improving the color fastness and water resistance of water-based pigment inkjet ink.

[0042] In summary, the present application includes at least one of the following beneficial technical effects:

[0043] 1. Water-based polyurethane is conducive to forming a durable film on the wall of water-based pigment inkjet ink, making it difficult for water droplets to penetrate, thereby improving the waterproofness of water-based pigment inkjet ink. In addition, water-based polyurethane contains more polar groups, which is convenient for cross-linking reaction to form a stable cross-linking structure to consolidate the internal structure of water-based pigment inkjet ink, so that the stability of the internal structure of inkjet ink can be improved, thereby improving the color fastness and water resistance of inkjet ink. Secondly, under the action of wetting agent, the surface tension of water-based pigment inkjet ink can be reduced, so as to further improve the stability of inkjet ink, thereby improving the spray The overall fluidity of the inkjet ink is improved, so that the spraying effect of the inkjet ink is improved, which is conducive to achieving better printing effect and adhesion effect. Moreover, under the adjustment of the pH adjuster, the inkjet ink is further maintained stable, which is conducive to further improving the spraying effect and color fastness of the inkjet ink. At the same time, the compatibility of the inkjet ink system is improved through the first solvent, so that the internal structure stability of the inkjet ink is further improved, and the inkjet ink is provided with a moisturizing effect, so that the fluidity of the inkjet ink is improved, thereby achieving a further improvement in the spraying effect and color fastness of the water-based pigment inkjet ink;

[0044] 2. Under the modification of quaternized chitosan, it is beneficial to improve the film-forming property of waterborne polyurethane. At the same time, quaternized chitosan has good hydrophilicity and compatibility, which is beneficial to improve the compatibility of waterborne polyurethane in waterborne pigment inkjet ink system. Through the dispersing effect of quaternized chitosan, waterborne polyurethane can be evenly dispersed in the inkjet ink system, so as to further improve the stability of inkjet ink and make inkjet ink uniformly film-formed, thereby further improving the color fastness and water resistance of waterborne pigment inkjet ink. Secondly, through the moisturizing effect of chitosan, the overall fluidity of inkjet ink can be effectively improved, which is beneficial to further improve the spraying effect of waterborne pigment inkjet ink, so that waterborne pigment inkjet ink can achieve better printing effect and adhesion effect. Moreover, under the antibacterial effect of chitosan, the reproduction of various algae bacteria can be reduced to reduce the influence of bacteria on the stability of inkjet ink, thereby further realizing the improvement of spraying effect and color fastness of waterborne pigment inkjet ink.

[0045] 3. The combination of citric acid and tartaric acid in a specific ratio enables the two to produce an alternating copolymer through polycondensation, thereby improving the structural stability, and effectively modifying the quaternary ammonium chitosan under the catalytic action of the catalyst, thereby effectively improving the surface activity and dispersibility of the quaternary ammonium chitosan, so as to give full play to the modification and dispersing effect of the quaternary ammonium chitosan on the water-based polyurethane, thereby further improving the internal structural stability and film-forming property of the inkjet ink, which is conducive to further improving the spraying effect and color fastness of the water-based pigment inkjet ink, and both citric acid and tartaric acid can be used as quaternary ammonium The invention relates to a cross-linking agent for quaternized chitosan and water-based polyurethane, thereby allowing the quaternized chitosan and the water-based polyurethane to undergo a cross-linking reaction, further giving full play to the modification effect of the quaternized chitosan on the water-based polyurethane, further improving the film-forming property of the water-based polyurethane, and being beneficial to improving the tightness of the connection of the internal structure of the water-based pigment inkjet ink, thereby further improving the color fastness and water resistance of the water-based pigment inkjet ink, and at the same time effectively exerting the moisturizing effect of the quaternized chitosan, further improving the overall fluidity of the inkjet ink, and further being beneficial to further improving the spraying effect of the water-based pigment inkjet ink. DETAILED DESCRIPTION

[0046] The present application is further described in detail below with reference to the embodiments.

[0047] The water-based polycarbonate polyurethane uses TAKELAC W-5145 from Mitsui of Japan;

[0048] The water-based polyether polyurethane uses TAKELAC W-6061 from Mitsui of Japan;

[0049] The polyether siloxane copolymer uses DOWSIL57 Additive from Dow Chemical of the United States;

[0050] The water-based resin-free color paste uses organic pigment resin-free color paste from Cabot of the United States.

[0051] Preparation Example

[0052] Preparation Example 1

[0053] Preparation of polyester-polyether mixed waterborne polyurethane:

[0054] 1.2 kg of deionized water and 0.02 kg of triethanolamine were stirred and mixed to obtain a weak alkaline solution; then, 0.1 kg of water-based polycarbonate polyurethane and 0.1 kg of water-based polyether polyurethane were added to the weak alkaline solution and stirred and mixed for 30 minutes to obtain a polyester-polyether mixed water-based polyurethane.

[0055] Preparation Example 2

[0056] Preparation of polyester-polyether mixed waterborne polyurethane:

[0057] 1.8 kg of deionized water and 0.07 kg of triethanolamine were stirred and mixed to obtain a weak alkaline solution; then, 0.2 kg of water-based polycarbonate polyurethane and 0.2 kg of water-based polyether polyurethane were added to the weak alkaline solution and stirred and mixed for 40 minutes to obtain a polyester-polyether mixed water-based polyurethane.

[0058] Preparation Example 3

[0059] Preparation of organic acid modified quaternary ammonium chitosan:

[0060] 0.7 kg of organic acid and 0.15 kg of sodium hypophosphite were added to 5.5 kg of deionized water, heated to 55°C, and stirred for 30 minutes; then, 0.3 kg of N-trimethyl chitosan was added, and the mixture was stirred for 1 hour; after the reaction, the mixture was precipitated with ethanol, washed and filtered, and then the filter was collected and dried in a vacuum oven at 55°C for 1 hour to obtain organic acid-modified quaternized chitosan;

[0061] Among them, the organic acid consists of 0.38 kg of citric acid and 0.32 kg of tartaric acid.

[0062] Preparation Example 4

[0063] Preparation of organic acid modified quaternary ammonium chitosan:

[0064] 1.8 kg of organic acid and 0.3 kg of sodium hypophosphite were added to 6.5 kg of deionized water, heated to 65°C, and stirred for 40 minutes; then, 0.8 kg of N-trimethyl chitosan was added and stirred for 2 hours; after the reaction, ethanol was used for precipitation, washing and filtering, and then the filter was collected and dried in a vacuum drying oven at 55°C for 1 hour to obtain organic acid-modified quaternized chitosan; wherein the organic acid was composed of 1.08 kg of citric acid and 0.72 kg of tartaric acid.

[0065] Preparation Example 5

[0066] Preparation of organic acid modified quaternary ammonium chitosan:

[0067] The difference between this preparation example and preparation example 4 is that 1.8 kg of citric acid is specifically selected as the organic acid.

[0068] Preparation Example 6

[0069] Preparation of organic acid modified quaternary ammonium chitosan:

[0070] The difference between this preparation example and preparation example 4 is that 1.8 kg of tartaric acid is specifically selected as the organic acid.

[0071] Preparation Example 7

[0072] Preparation of chitosan modified waterborne polyurethane:

[0073] 0.18 kg of the organic acid-modified quaternized chitosan of Preparation Example 3 and 4.5 kg of the polyester-polyether hybrid waterborne polyurethane of Preparation Example 1 were mixed evenly, heated to 70° C., and stirred for reaction for 2 h to obtain chitosan-modified waterborne polyurethane.

[0074] Preparation Example 8

[0075] Preparation of chitosan modified waterborne polyurethane:

[0076] 0.26 kg of the organic acid-modified quaternized chitosan of Preparation Example 4 and 6.5 kg of the polyester-polyether hybrid waterborne polyurethane of Preparation Example 2 were mixed evenly, heated to 85° C., and stirred for reaction for 3 hours to obtain chitosan-modified waterborne polyurethane.

[0077] Preparation Example 9

[0078] Preparation of chitosan modified waterborne polyurethane:

[0079] The difference between this preparation example and preparation example 8 is that the organic acid-modified quaternary ammonium chitosan is specifically the organic acid-modified quaternary ammonium chitosan prepared in preparation example 5.

[0080] Preparation Example 10

[0081] Preparation of chitosan modified waterborne polyurethane:

[0082] The difference between this preparation example and preparation example 8 is that the organic acid-modified quaternary ammonium chitosan is specifically the organic acid-modified quaternary ammonium chitosan prepared in preparation example 6.

[0083] Preparation Example 11

[0084] Preparation of chitosan modified waterborne polyurethane:

[0085] The difference between this preparation example and preparation example 8 is that an equal amount of quaternized chitosan is used to replace the organic acid-modified quaternized chitosan in preparation example 4, that is, the organic acid-modified quaternized chitosan in preparation example 4 is not added, and 0.26 kg of quaternized chitosan is added.

[0086] Preparation Example 12

[0087] Preparation of chitosan modified waterborne polyurethane:

[0088] The difference between this Preparation Example and Preparation Example 8 is that an equal amount of water-based polycarbonate polyurethane is used to replace the polyester-polyether mixed water-based polyurethane in Preparation Example 2, that is, the polyester-polyether mixed water-based polyurethane in Preparation Example 2 is not added, and 6.5 kg of water-based polycarbonate polyurethane is added.

[0089] Preparation Example 13

[0090] Preparation of chitosan modified waterborne polyurethane:

[0091] The difference between this Preparation Example and Preparation Example 8 is that an equal amount of water-based polyether polyurethane is used to replace the polyester-polyether mixed water-based polyurethane in Preparation Example 2, that is, the polyester-polyether mixed water-based polyurethane in Preparation Example 2 is not added, and 6.5 kg of water-based polyether polyurethane is added.

[0092] Example

[0093] Example 1

[0094] Preparation of a water-based pigment inkjet ink suitable for walls:

[0095] First, 1kg of ethylene glycol, 2kg of deionized water, 0.01kg of bactericide MBT-25 and 0.01kg of ammonia water were stirred and mixed at a speed of 500r / min for 20min, and then 0.05kg of polyether siloxane copolymer was added, and stirred at a speed of 500r / min for 20min to obtain a clear liquid; secondly, 1kg of chitosan-modified polyurethane of Preparation Example 7 was added, and stirred at a speed of 500r / min for 30min, and then 1.5kg of water-based resin-free color paste was added, and stirred at a speed of 500r / min for 30min to obtain an inkjet ink preform; then, at 0.02MPa, a negative pressure filter was used to negatively filter the inkjet ink preform through the superposition of an upper hydrophilic filter membrane of 0.45μm and a lower hydrophilic filter membrane of 0.22μm, and finally the filtrate was collected to obtain a water-based pigment inkjet ink suitable for walls;

[0096] Among them, Carbot400 is used as the water-based resin-free color paste.

[0097] Example 2

[0098] Preparation of a water-based pigment inkjet ink suitable for walls:

[0099] First, 3kg of ethylene glycol, 5kg of deionized water, 0.1kg of bactericide MBT-25 and 0.1kg of ammonia water were stirred and mixed at a speed of 500r / min for 30min, and then 0.3kg of polyether siloxane copolymer was added, and stirred at a speed of 500r / min for 30min to obtain a clear liquid; secondly, 2kg of chitosan-modified polyurethane of Preparation Example 8 was added, and stirred at a speed of 500r / min for 40min, and then 3.5kg of water-based resin-free color paste was added, and stirred at a speed of 500r / min for 40min to obtain an inkjet ink preform; then, at 0.02MPa, a negative pressure filter was used to negatively filter the inkjet ink preform through the superposition of an upper hydrophilic filter membrane of 0.45μm and a lower hydrophilic filter membrane of 0.22μm, and finally the filtrate was collected to obtain a water-based pigment inkjet ink suitable for walls;

[0100] Among them, the water-based resin-free color paste uses Carbot450C.

[0101] Example 3

[0102] Preparation of a water-based pigment inkjet ink suitable for walls:

[0103] The difference between this embodiment and embodiment 2 is that the water-based resin-free color paste of this embodiment is specifically Carbot465M.

[0104] Example 4

[0105] Preparation of a water-based pigment inkjet ink suitable for walls:

[0106] The difference between this embodiment and embodiment 2 is that the water-based resin-free color paste of this embodiment is specifically selected from Carbot470Y.

[0107] Example 5

[0108] Preparation of a water-based pigment inkjet ink suitable for walls:

[0109] The difference between this embodiment and embodiment 2 is that an equal amount of the polyester-polyether hybrid waterborne polyurethane of preparation example 2 is used to replace the chitosan modified polyurethane of preparation example 8, that is, the chitosan modified polyurethane of preparation example 8 is not added, and 1 kg of the polyester-polyether hybrid waterborne polyurethane of preparation example 2 is added.

[0110] Example 6

[0111] Preparation of a water-based pigment inkjet ink suitable for walls:

[0112] The difference between this example and Example 2 is that the chitosan modified polyurethane of Preparation Example 8 is replaced by an equal amount of the chitosan modified polyurethane of Preparation Example 9, that is, the chitosan modified polyurethane of Preparation Example 8 is not added, and 2 kg of the chitosan modified polyurethane of Preparation Example 9 is added.

[0113] Example 7

[0114] Preparation of a water-based pigment inkjet ink suitable for walls:

[0115] The difference between this example and Example 2 is that the chitosan modified polyurethane of Preparation Example 8 is replaced by an equal amount of the chitosan modified polyurethane of Preparation Example 10, that is, the chitosan modified polyurethane of Preparation Example 8 is not added, and 2 kg of the chitosan modified polyurethane of Preparation Example 10 is added.

[0116] Example 8

[0117] Preparation of a water-based pigment inkjet ink suitable for walls:

[0118] The difference between this example and Example 2 is that the chitosan modified polyurethane of Preparation Example 8 is replaced by an equal amount of the chitosan modified polyurethane of Preparation Example 11, that is, the chitosan modified polyurethane of Preparation Example 8 is not added, and 2 kg of the chitosan modified polyurethane of Preparation Example 11 is added.

[0119] Example 9

[0120] Preparation of a water-based pigment inkjet ink suitable for walls:

[0121] The difference between this example and Example 2 is that the chitosan modified polyurethane of Preparation Example 8 is replaced by an equal amount of the chitosan modified polyurethane of Preparation Example 12, that is, the chitosan modified polyurethane of Preparation Example 8 is not added, and 2 kg of the chitosan modified polyurethane of Preparation Example 12 is added.

[0122] Example 10

[0123] Preparation of a water-based pigment inkjet ink suitable for walls:

[0124] The difference between this example and Example 2 is that the chitosan modified polyurethane of Preparation Example 8 is replaced by an equal amount of the chitosan modified polyurethane of Preparation Example 13, that is, the chitosan modified polyurethane of Preparation Example 8 is not added, and 2 kg of the chitosan modified polyurethane of Preparation Example 13 is added.

[0125] Comparative Example

[0126] Comparative Example 1

[0127] The difference between this embodiment and embodiment 2 is that no water-based polyether polyurethane is added.

[0128] Performance test data

[0129] The water-based pigment inkjet inks prepared in Examples 1-10 of the present application and Comparative Example 1 were spray-printed on the treated prefabricated wall tiles, and then baked at 150° C. for 3 minutes to obtain image home decoration semi-finished products.

[0130] Test 1: The image home furnishing semi-finished products of Examples 1-10 and Comparative Example 1 were tested for dry rubbing color fastness; a dry bleached plain cloth was used to rub the image home furnishing semi-finished products back and forth 10 times, and then the original rubbing cloth and the dry rubbing color samples were cut out, and the color fastness grade of the rubbing cloth was evaluated by using a gray sample card in a standard light source light box to evaluate the color fastness of the rubbing cloth. Among them, the dry rubbing color fastness grade is divided into 5 grades, namely 1, 2, 3, 4, and 5. The higher the grade, the better the dry rubbing color fastness of the water-based pigment inkjet ink. The test results are shown in Table 1.

[0131] Test 2: The image home furnishing semi-finished products of Examples 1-10 and Comparative Example 1 were tested for dry rubbing color fastness; the bleached plain cloth was soaked in water in advance, and its liquid carrying rate was controlled to be 70%, and then the bleached plain cloth was used to rub the image home furnishing semi-finished products back and forth 10 times, and then the original rubbing cloth and the wet rubbing color sample were cut, and the wet cloth was dried at 50°C, and finally the color fastness grade of the rubbing cloth was evaluated by using a gray sample card for color staining in a standard light source light box. Among them, the wet rubbing color fastness grade is divided into 5 grades, namely 1, 2, 3, 4, and 5. The higher the grade, the better the wet rubbing color fastness of the water-based pigment inkjet ink. The test results are shown in Table 1.

[0132] Test 3: The printing stability test was performed on the aqueous pigment inkjet inks prepared in Examples 1-10 and Comparative Example 1; the aqueous pigment inkjet inks prepared in Examples 1-10 and Comparative Example 1 were respectively placed in an inkjet printer, and then the inkjet printer was subjected to a wiredrawing oblique spraying test, and the state of the wiredrawing oblique spraying of the nozzles in the printer nozzle was recorded. The test results are shown in Table 1.

[0133] Table 1 Summary of performance test results

[0134] Sample Dry rubbing color fastness Wet rubbing color fastness Drawing oblique spray state Example 1 4 3-4 No obvious brushing Example 2 4-5 4 No obvious brushing Example 3 4-5 4 No obvious brushing Example 4 5 4-5 No obvious brushing Example 5 3 2-3 Slightly brushed 7 holes Example 6 4 3-4 Slightly brushed 3 holes Example 7 4 3 Slightly brushed 3 holes Example 8 3-4 3 Slightly brushed 5 holes Example 9 4-5 3-4 No obvious brushing Example 10 4 3-4 No obvious brushing Comparative Example 1 2-3 1-2 Slightly brushed 13 holes

[0135] Combining Example 2 with Comparative Example 1 and the data in Table 1, it can be seen that the present application modifies quaternized chitosan by combining citric acid and tartaric acid in a specific ratio to obtain organic acid-modified quaternized chitosan, and then obtains a water-based pigment inkjet ink with high color fastness, water resistance and good stability by composite modification of the organic acid-modified quaternized chitosan and polyester-polyether mixed waterborne polyurethane, thereby obtaining a water-based pigment inkjet ink with good spraying effect and capable of stably adhering to the wall.

[0136] Combining Example 2 with Examples 5-8 and the data in Table 1, it can be seen that compared with Comparative Example 1, the color fastness, water resistance and spraying effect of Example 5 are improved, but relative to Example 2, the improvement is small, indicating that the addition of polyester-polyether mixed waterborne polyurethane alone has little promoting effect on the color fastness, water resistance and stability of inkjet ink; and according to Example 8, it can be seen that the modification of polyester-polyether mixed waterborne polyurethane by chitosan alone has no obvious effect on improving the color fastness and stability of inkjet ink, indicating that organic acid is required to modify chitosan to achieve better results. At the same time, according to Examples 6-7, when citric acid and tartaric acid are combined in a specific ratio to modify chitosan, the modification effect of chitosan on polyester-polyether mixed waterborne polyurethane can be effectively improved, thereby effectively further improving the color fastness and water resistance of inkjet ink, and effectively improving the stability of inkjet ink, so that the overall fluidity of inkjet ink is improved, thereby achieving an improvement in the spraying effect.

[0137] Combining Example 2 with Examples 9-10 and the data in Table 1, it can be seen that in the present application, when the water-based polycarbonate polyurethane and the water-based polyether polyurethane are combined in a weakly alkaline solution in a specific proportion, it is beneficial to improve the adhesion and water resistance of the inkjet ink, thereby achieving a further improvement in the color fastness of the water-based pigment inkjet ink.

[0138] The above are all preferred embodiments of the present application. The embodiments are only explanations of the present application and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A water-based pigment inkjet ink suitable for walls, characterized in that: Contains the following raw materials in parts by weight: 10-20 parts of chitosan modified waterborne polyurethane; Wetting agent 0.5-3 parts; 0.1-1 part of fungicide; pH regulator 0.1-1 part; 15-35 parts of water-based resin-free color paste; 10-30 parts of the first solvent; 20-50 parts of deionized water; The raw materials for preparing the chitosan-modified waterborne polyurethane include organic acid-modified quaternized chitosan and waterborne polyurethane, and the weight ratio of the organic acid-modified quaternized chitosan and waterborne polyurethane is (1.8-2.6):(45-65); the raw materials for preparing the organic acid-modified quaternized chitosan include quaternized chitosan, an organic acid and a catalyst, and the weight ratio of the quaternized chitosan, the organic acid and the catalyst is (3-8):(7-18):(1.5-3); the organic acid includes citric acid and tartaric acid, and the weight ratio of citric acid to tartaric acid is (1.2-1.5):

1.

2. The water-based pigment inkjet ink suitable for walls according to claim 1, characterized in that: The quaternized chitosan is selected from N-trimethyl chitosan.

3. The water-based pigment inkjet ink suitable for walls according to claim 1, characterized in that: The waterborne polyurethane is a polyester-polyether mixed waterborne polyurethane. The raw materials for preparing the polyester-polyether mixed waterborne polyurethane include waterborne polycarbonate polyurethane, waterborne polyether polyurethane, deionized water and weakly alkaline amine compounds. The weight ratio of the waterborne polycarbonate polyurethane, waterborne polyether polyurethane, deionized water and weakly alkaline amine compounds is (1-2): (1-2): (12-18): (0.2-0.7).

4. A method for preparing a water-based pigment inkjet ink suitable for walls, characterized in that: The method for preparing a water-based pigment inkjet ink suitable for walls according to any one of claims 1 to 3 comprises the following steps: First, the first solvent, deionized water, bactericide and pH regulator are stirred and mixed for 20-30 minutes, and then a wetting agent is added and stirred for 20-30 minutes to obtain a clear liquid; then, chitosan-modified water-based polyurethane is added and stirred for 30-40 minutes, and then a water-based resin-free color paste is added and stirred for 30-40 minutes to obtain an inkjet ink preform; finally, the inkjet ink preform is negatively pressure filtered at 0.02-0.06MPa through a double-layer hydrophilic filter membrane, and the filtrate is collected to obtain a water-based pigment inkjet ink suitable for walls.

5. The method for preparing a water-based pigment inkjet ink suitable for walls according to claim 4, characterized in that: The waterborne polyurethane is a polyester-polyether mixed waterborne polyurethane, and the preparation method of the polyester-polyether mixed waterborne polyurethane is as follows: deionized water and a weakly alkaline amine compound are stirred and mixed to obtain a weakly alkaline solution; then, waterborne polycarbonate polyurethane and waterborne polyether polyurethane are added to the weakly alkaline solution, and stirred and mixed for 30-40 minutes to obtain a polyester-polyether mixed waterborne polyurethane.

6. The method for preparing a water-based pigment inkjet ink suitable for walls according to claim 5, characterized in that: The preparation method of the organic acid modified quaternary ammonium chitosan is as follows: adding an organic acid and a catalyst into deionized water, heating to 55-65°C, and stirring and mixing for 30-40 minutes; then, adding quaternary ammonium chitosan, stirring and reacting for 1-2 hours; after the reaction is completed, precipitating with ethanol, washing and filtering, and then collecting and drying the filter to obtain the organic acid modified quaternary ammonium chitosan, wherein the weight ratio of the quaternary ammonium chitosan, the organic acid, the catalyst and the deionized water is (3-8): (7-18): (1.5-3): (55-65).

7. The method for preparing a water-based pigment inkjet ink suitable for walls according to claim 6, characterized in that: The preparation method of the chitosan modified waterborne polyurethane is as follows: organic acid modified quaternary ammonium chitosan and polyester-polyether mixed waterborne polyurethane are uniformly mixed, heated to 70-85° C., stirred and reacted for 2-3 hours to obtain the chitosan modified waterborne polyurethane.